Eventide H3000 D/SE Ultra Harmonizer Repair : No Audio and Buzzing Noise Can We Fix It?

[@roberttodd2414]

this is the type of kit i'd love to learn and spend my life repairing

[@5pr1nk57]

Ooh yeah, this one's a bit of me Richard, lovely machines they are!

[@Dutch_off_grid_homesteading]

Heya, well not a repair for now but I really love to see this ( even do I don't get it, my shortcoming ) but I would like to learn this kind of elektronics more.

[@g4z-kb7ct]

28:50 The DSP is a common TMS32010. These often have internal ROM (almost always protected). Pin 3 on the chip selects the ROM mode, grounded=external rom, tied to vcc=internal rom. If working, the data bus and address bus will be very active. Pin 33 MEM_EN is the chip enable, clock is pin 8 and reset is pin 4.

[@LearnElectronicsRepair]

Thanks for the info - everything helps

[@5pr1nk57]

'Soft Knob' 😂 The ICs marked 'BB' are Burr Brown DACs, very nice!

[@andymouse]

Love BB :)

[@00Skyfox]

The processor in the Commodore 64 was the 6510, which is a variation of the 6502.

[@rlgrlg-oh6cc]

I repaired one of these in 2019. The problem ended up being the DSP chips and some SRAMs. I bought the replacement parts on ebay. The RAMs were Holtek HT6116-70 and CY7C128A-45. At that time it was easy to find those parts on ebay. I didn't have the Self Test EPROM.

[@lonndawg7554]

Richard this is going to be an interesting repair... We are dealing with analog to digital circuitry plus, these EPROMS... It's interesting that the designers of this product are using software, maybe to some degree this would help technicians at their factory repair facilities to diagnose issues quicker... But that's just speculation, for the most part don't you think that this entire product and what it does could have been designed with primarily IC's and analog to digital converters and pretty much not need the EPROMS...? Also what I do like is the socketed in IC's... for repair technicians that can be so good to just swap the IC's and see if the behavior changes. That's one thing about stereo equipment is there is a left and a right channel and you can compare the two. I look forward to resolving what's going on with this device. and if we can... Can we use the scope to see what kind of signals you might expect from a digital output at least discussing it. ? Maybe what a technician would be looking for to just know that the digital output seems to be working? I don't want to make an assumption that just because you have a signal on the oscilloscope that it would prove the circuit is working, but that's where we need a discussion......

[@LearnElectronicsRepair]

From what I see once the stereo audio goes into the digital side of things there are no two channels to compare anymore. I was chatting with Det today, those 74S288 ROMS (not eproms) that apparecntly configure the three PELs are 32x8 byte and not erasable. None of the eprom programmers we have between us can read these ICs but the RCT (retro chip tester) I have that is almost complete can identify and dump them - though it can't program them either. Then there is availability or not of the firmware. I'm hoping the problem is in the timing circuitry but there are so many unknowns with this one

[@dosh2222]

Hi Rich, I found the dump of SELF TEST EPROM for you... how I can send to you? I cannot add link here.... I try to point you to the link on the live stream today, but i don't know if you get it....

[@stavehow5501]

The first thing i do with this type of equipment is re-seat all ic's in sockets. I have found this fixes the problems more than half the time. I would think in your salty environment this would be an even bigger problem.

[@5pr1nk57]

Try reaching out to my old neighbour and one of my childhood electronics tutors and idols who I thank/blame for getting me further into both electronics and audio gear and synths, a somewhat known tech going by the name of Kent Spong! 😉

[@reneandra9294]

this is the same family of chips, where i found the self overclocking quartz. check if the clock is in spec, it should be very close. as i understand, there should be a latch somewhere, responsible for dividing the clock to the different TI cpu's, i would start there. pay attention to the voltage rails too. i've seen there are 2x -5volt rails. possibly one is missing. very interesting video!

[@truthreigns7]

i have faith in you, i am sure you can fix it if the device is fixable at all.

[@TheEmbeddedHobbyist]

at around 6.14s in U3 is an 8-bit multiplying DAC, being used as a volume control. in stead of suppling Vref with a stable voltage so it works as a normal Digital Analogue Converter (DAC) you feed your audio signal on the the Vref pin. This gives you the ability to adjust the output with 256 steps. We used to do this with cards full of DAC's to provide audio volume control of coms radio inputs. very common method in the 80's when digital control was in its infancy.

[@andymouse]

🐁😘 LOL Squeak !!

[@LearnElectronicsRepair]

Thanks for the info

[@Audiofix101]

It looks to me like you are testing the output XLR's at the wrong pin the out pin is opposite of the input pin from left to right pin3= none inv in 2= inverted in pin1= gnd in. then output's 1=gnd, 2=inv in, 3 non inv in.

[@mitkothemacedonian]

The opamps are socketed so that one can replace TL072s with OPA2134 and NE5532s with LM4562s

[@andymouse]

Or even better OPA1656 !

[@g4z-kb7ct]

33:26 Those smaller chips with stickers are bipolar PROMs. Likely 82S123 or similar. They may be the external ROM for the TMS. The TMS has a 16-bit databus so it requires data from 2x 8-bit ROMs to give 16-bits of data which is probably why they are in pairs. One will be providing D0-D7 and the other D8-D15. They can be read with a proper EPROM programmer (junk chinese ones don't support bipolar PROMs) but good luck finding a correctly dumped backup on the net ;-)

[@LearnElectronicsRepair]

74S288 I believe. The only 'programmer' I have that can identify and dump these is my RCT which is almost complete, it was a DIY project I guess I really need to finish

[@g4z-kb7ct]

@LER yeah the 288 is the same as 82s123. RCT only lists one type in menu but the docs list all supported types. Ummm yeah the RCT is the ducks nuts, you have not yet realised how important this piece of equipment is or you would have built it by now. I built one about 4 years ago and it paid for itself 100X so far.

[@LearnElectronicsRepair]

@@g4z-kb7ct I have the whole thing assembled just missing the '12V module' from the top left of the PCB. I'll get one ordered after the weekend, the project has been sitting on one side for some time just due to being busy with other stuff really. That's the way it always seems to be lol 🙄

[@g4z-kb7ct]

@LER I actually reversed that little module. It's just a buck boost circuit, it takes 5V from the lower board and boosts to plus 12V and minus 12V. These are really useful for any kind of random voltage project. Minus 12V is particularly difficult to obtain now with any off-the-shelf new product so this is a good way to get that. I used one of these to fix an arcade game Defender that uses a strange DAC that requires -12V. If you are interested have a look at the schematic I published of the boost circuit. You can set the voltage using some resistors to achieve any voltage you want. The part number to buy them is DD1718PA. btw when you power the rct use the dc barrel jack with 7.5V with at least 500mA, or 9V at 500mA or 1A.The usb power input is convenient for 5v devices but is not good enough if you want to test or program some chips like 2708 eproms. You would probably never need to do that in your line of work but I often need to program a 2708 eprom to fix some old piece of crap and the rct is probably the only modern device that can do it nowadays.

[@LearnElectronicsRepair]

@@g4z-kb7ct Thanks for the info on the module, I'm also in touch with Stephan who designed the RCT. I have one of the older TL866A programmers as well as the TL866+ii the older one handles old eproms with 27V programming pulse (I think 2708 is one of that family) Carlos from Retro Upgrade borrowed it to program some 27xx for his old Vecrtrex I think it was called

[@danblankenship5744]

There are a lot of old tantalum capacitors. A quick check might reveal a shorted one (thermal camera?).

[@wittsy]

hey have you ever looked at an xbox wifi card to repair it ? is it possible

[@therealspixycat]

Check to see if the eproms are actually read at start up

[@rainwater397]

There are some good suggestions here. I always follow the power up procedures. Can you test the startup circuit to ensure rst is doing what it needs for the brain chip to startup?

[@LearnElectronicsRepair]

IMHO the 'brain' processor is running correctly, it's the DSP sectopn that isn't. I will be working through the service manual tests on the next video anyway

[@g4z-kb7ct]

27:48 That's a common 6809 CPU. The Commodore 64 uses a 6510 which is a modified 6502 CPU.

[@LearnElectronicsRepair]

Yeah I thought it was like a 6805 which I thought the C64 used but tha twas a long time ago

[@g4z-kb7ct]

@@LearnElectronicsRepair there's no such thing as a 6805 cpu. there is 6800 which was used in early Bally pinball machines. 6801 is same as 6800 with internal rom. 6802 and 6808 are equivalent but one has 128 bytes of ram built in and the other doesn't. 6809 has 2 offset main clocks. The later versions require external E and Q clocks and the earlier 68A09 provides its own E and Q clock. In previous repairs I've found if the E or Q clock is missing the cpu burns up. The 6809 was used in a few early 80's home computers too, like the Tandy Coco, Dragon 32 etc and arcade games like Defender, Joust, Gyruss and many others.

[@LearnElectronicsRepair]

@@g4z-kb7ct Yeah my mistake, now I recall it was a 6502 or a variant thereof in the C64. I beleive the BBC Micro uses the same CPU, I never owned one but a lad I worked with had one and we used to argue whether my Sepctrum 48 was better lol. I never programmed 6502 assembly code, I thought the cpu didn't have enough registers 😛 I learned assembly on the Z80 of course. Your knowledge of arcade machines sounds like another guy who used to post a lot here, Mr Guru. Are you one and the same?

[@g4z-kb7ct]

@@LearnElectronicsRepair yeah that's me, but now incognito ;-)

[@LearnElectronicsRepair]

@@g4z-kb7ct Well it's good to hear you are still around. 🙂

[@Karthor.]

lol at the soft knob

[@LearnElectronicsRepair]

😂😂😂

[@danieljohnson8437]

Excellent R

[@joepiscapo936]

A tds scope would give you the frequency reading so fast...as per manual.

[@TheEmbeddedHobbyist]

There is all so by the look of it a "BQ4010" 40pin tall chip which could be a NVRAM, Non Volatile Random Access Memory and it large size is in the fact that it has a Lithium cell within it. data retention for > 10years. On their first power up an isolation barrier gets broken and the internal battery connected. then it 10years or so from this point. Is there a date code on the chip as it could be forgetting data by now.

[@BREN2009]

Hi very good to watch I have a special inspection drone that has a fault somewhere on the main board it's never been crashed or wet iv been told by the manufacturer that a hot plug in of the battery has been known to blow a few ic chips would you have a go at finding the fault and repairing it for me I will obviously pay you for your time/parts it is way too expensive for the manufacturer to repair it for me I have removed the boards from the body so it can all be wired together out of its shell I would send the full drone I can't see anything visually wrong although I'm not good at component level repairs yet only basic soldering and basic multimeter use thanks.

[@nickk6109]

Eventide Harmoniser was a guitar effect that Steve Vai used heavily in those days - check out Steve Vai Passion & Warfare: kzbin.info/www/bejne/a3vQmWqQoJJ1q5Y

[@ralphj4012]

The digital-looking output on the DAC was odd, though the frequency and amplitude weren't clear. I'm sure you checked all the DAC supply voltages and swapped the audio input to see if anything came out the other DAC. The tants fail on these and take out the DACs, allegedly.

[@LearnElectronicsRepair]

Yeah the supply voltages all read OK

[@mickeythompson9537]

Perhaps I missed something, but you mention the owner using this with a microphone? I'm pretty sure this unit is not intended for microphone-level signals. Far too low and would need a pre-amp before it would function on a unit like this. Either way, I'd want to _listen_ to what's happening in this piece of audio gear, not just scope it.

[@LearnElectronicsRepair]

Yes. There are jumpers that set the input sensitivity according to the manual but I didn't look closely at them. He could be using a wireless mic also

[@mathiaskarlsson1837]

That one was really expensive if I remember correctly

[@g4z-kb7ct]

You don't need the test eprom. You can easily check if the thing is working simply br probing the various CPUs and RAMs........ the number one cause of faults in digital circuits is..... RAM. Check CPUs are active on address/databus, ROMs are being accessed (CS/OE enables), clocks/crystals, resets etc. There's also a LOT of logic. They are not particularly difficult to fix for a home person with years of knowledge and equipment (i.e. someone like me with 30 years arcade game repair experience), just pull and test every chip if necessary in a dedicated logic / ram / cpu tester. However for a repair business where time is money this is way too much work, especially when said repair business has limited experience with repairing old-school CPU-controlled PCBs like this. In short this is WAY above your pay-level and will be scrapped as there are very few people on the planet (I'm one of them) with the time and knowledge to deal with that ;-)

[@andymouse]

Yeah too much, glue everywhere. I wouldn't touch it personally from a business point of view. You need some kit and some time and a knowledge base to have a go at this. I think LOL! he might get lucky.

[@andymouse]

Do you know this chip NB3N3020 ? just curious !

[@LearnElectronicsRepair]

Excuse me but I worked as a component level repair engineer in the early to late 80s for ICL. I also fixed a lot of C64, Spectrum and Amiga as a hobby sideline at the same time. Don't you think you are being a bit insutling here?

[@rainwater397]

With a name like that, they are a robot or a minor. Eather way their just picking for a fight

[@IvanTheUndertaker]

Multiplying DAC?

[@totalbullion5882]

I would imagine some parts being impossible to acquire. I think there are certainly cheaper options out there for the customer in 2025.

[@LearnElectronicsRepair]

As I understand it these H3000 have a kinda legendary status in the music making community and are as much collectors items as they are practical, so I don't think the availability of cheaper modern options is a factor here. It probably like guitars, you can buy newer better models but some people still want the model that Jimi Hendrix, George Harrison or Eddie Van Halen played and are willing to pay a premium to have it. The same probably applies to some early music synthesizers as well.

[@hollybrumma6819]

H3000 is a legendary tool. ​@@LearnElectronicsRepair

[@sivoltage]

@@LearnElectronicsRepair the vintage synth market is huge.

[@nasosst3092]

That's exactly the case. You have to deal with a legend machine,, a unique studio tool, a product of a pioneering company

[@mickeythompson9537]

@@LearnElectronicsRepair Vintage audio gear would be an expensive and rather pointless thing to _collect_ - in fact, these things are still used in professional studios. 'Legendary' might be true, but they have a sound that people still want in their music, the nuances of which aren't quite replicable by modern gear.

[@roberttodd2414]

surely an eprom can be copied and cloned, with an emprom machine. if a=someone with a working eprom was willing to dump the info from the eprom they could run off as many copies as needed with a prommer?

[@fft2020]

I have no idea what an ultra harmonizer is

[@LoRentSound]

All of those tantalum capacitors have to go. I fix a ton of vintage synths and the tantalum capacitors are always bad.

[@LoRentSound]

I think you're spinning your wheels with the self test eprom. Replace the tantalums then go from there. Google H3000 tantalums. It's a known issue with these.

[@pantelis241]

Nice Video, can you repair automotive PCM ? Would you please make some videos about ECU / PCM ?

[@g4z-kb7ct]

They are of a similar complexity and not easy to repair due to using a lot of chips (some custom) and hybrid (ceramic) modules and of course there are no schematics. Rich can only repair what comes in from customers or his own stuff. Search around I'm sure YT has some ECU or similar vids.

[@LearnElectronicsRepair]

I have worked on ECU but only my own when I was into the custom/classic car scene for a few years until i left the UK. If i get the chance to take a look at one again I will but this is not something I specialise in.