Crown CDi1000 Professional Amplifier - Repair & Bench Testing (Ep. 11)

[@225savage0]

Oh man I’m fascinated with how you built that dummy load. I’m about to build one of those. I love this stuff.

[@Acoustic_Theory]

The fans in these are either off or on, with thermostat control, so if the amp isn't sitting hot enough to require airflow then the fan remains off. That probably helps them not to fill with dust.

[@duroxkilo]

nice work... for whoever is interested class D amps are to be tested for max power using pulses not continuous sine waves. there's nothing wrong w/ 'stress testing' them especially after a repair but the 'old' testing methodology offers erroneous results. in short, class D have a higher power density than class AB but they don't maintain max output for a prolonged time because it is not needed when used for audio. instead the amps put out 'power spikes' (by design) for long enough to accommodate even the most bass intensive programs.

[@mattsan70]

What you don't appear to realise is that the output heatsinks are sitting at B+ and B- - . The transistor collectors are NOT isolated from the heatsinks. That foam is to stop the lid shorting the heatsinks out - you keep putting you hand close to them. probably around +130v and -130v each.

[@TrevorsBench]

Yes, you're right.

[@225savage0]

Your signal light is illuminated just like the one that i received from eBay. The guy is sending me another one. I have another amp like it and the signal light doesn’t illuminate unless it’s connected to a source. I could take it apart and mess with it but He’s sending me another one. I heard it’s probably the front pcb board. Someone had the same problem and changing that fixed it.

[@Anzs17]

Hi Trevor, need your help, I have DSI 1000, its turning on & ready led is also glowing, but the fan is not starting up, Do I need to change the 2700uf Cap. Please suggest. (Note: I am only getting one relay click)

[@medovasar2072]

I have similar Crown just cdi2000 model that's inside exactly about the same as well so clean, used it for 9 years all good but one day fail dead, didn't turn ON, so I replaced the TL494C and that same cap you did 220uF 35V. It all worked good. However that burned area is my concern still. Same area exists in cdi2000 model, when you turn ON amp that area really heats up but amp is working just fine. Wonder if there is something else in the circuit causing that area to heat up so much! Any thoughts or ideas!!! Thanks!

[@TrevorsBench]

Just a poor design. Using resistors to drop a higher voltage to a lower one always wastes heat. Some people remove the resistors from the board and mount them off with a terminal strip so the heat is away from the board

[@medovasar2072]

@@TrevorsBench I've got 3W 48.7Kohm resistors to replace all 6 of current ones 1W. They can fit and will reduce heat insane on those. But there two more Q transistors in that same area, so I'm not sure what to do with those next. Will see!!!

[@danruiz902]

Tengo varios amplificadores de ese tipo, alguna recomendacion o info ya q son dificiles de reparar?

[@Usedtoyman_TFTA]

I have a few of these amps with this issue. Other videos claim only the first cap needs to be replaced and they suggest a 50V 220uf cap. I'm ready to do it but would like to know how to determine if the amp has any loads in it so I don't kill myself. Do you have a video or suggestion on how to learn how to figure out if an amp has a load and how to disipate it? You feel replacing all the other caps is necessary?

[@TrevorsBench]

Hi Brian. Good on you for raising your safety concerns before proceeding. You will need a voltmeter and test for voltage present on the two large capacitors, 2700uf at 200v I believe. Most likely, you'll find the caps are already discharged and read a volt or less = safe to proceed If there is a higher voltage on the caps, you could discharge them by shorting a 100 ohm resistor across the terminals. FYI, the risk of getting electric shock from voltages below 50v is nil but there may still be enough energy stored to do damage if there was a short circuit The caps I replaced in this amp were faulty and I determined this by testing. No two amps will fail in exactly the same way.

[@endurokrasnobrod4291]

Hi! I'm struggling with my cdi1000, it's already turned on, but the display doesn't work at all, can you help me, what could be the problem?

[@225savage0]

2 100 watt resisters for the dummy load. Got it!

[@miguemikemoreno]

where did you found the 48.7k 1W resistors? i need to replece those to

[@reda19891]

why are the signal lights lighting up intermittently with no signal in? i have a few CDi1000s that does the same thing

[@TrevorsBench]

Don't know

[@alexandrebarros1032]

Hello Trevor's, I'm Alexandre and I live in Brazil. I'm going to follow your channel. I also carry out repairs on amplifiers, then if possible we will exchange information, thank you.

[@TrevorsBench]

Hi Alexandre, you can find my email in my home page. Thanks for watching

[@revbradl]

I have this same Amp but it won't power on at all. I see heat scorching in the same place around the power switch. Can you verify which caps I need to buy -- you said C196, but I want to make sure to order the right ones. Thanks in advance.

[@revbradl]

nvrmind, I reviewed the video and clearly heard you say 220uf, 35v cap. I am ordering them now. Hoping this is all that is necessary to get my amp going again.

[@Steveh112]

Have you ever seen one of these stuck in a "Low Line" message on the display? My line voltage is good and the spare amp works good in it's place, so the problem is definitely in the amp itself. I found and replaced several bad electrolytic capacitors including the 220uf 35V near the power switch and a 470uf 35V which measured wide open on an ESR meter. But after replacing all the bad ones, I still have the same issue. Is there a schematic or service manual for this model available anywhere? The Crown website has nothing on the CDi series. Thanks

[@marshallhance463]

Hey! Anything ever come up with this? I have the exact problem with my xti4002. I turn it on and then get the “lo line” message with a blinking power light! Any help is appreciated! RockNroll! Edit: all my caps are still in tolerance so trying to find a clue on where to check next.

[@TrevorsBench]

I expect the message LOW LINE refers to the output setting and not a fault indication? I'm guessing here. The CDI1000 has a a rather complicated user interface. The owners manual should steer you to what the message means

[@Steveh112]

@@TrevorsBench I got this one fixed a few days after posting this comment. Turned out to be something a little complicated: C76, the capacitor that goes directly across the cooling fan was dead shorted, which shorted the driver transistors, several in parallel driving the fan. 3/4 of them shorted out so I replaced all of them. The base of these driver transistors is driven by U17. The other half of U17 is what monitors the rail for the line voltage. I believe it was damaged by the dead shorted load across the output of the other half of it. After replacing it with a new IC, the output changed from low and unstable to a good solid output well above the .7V threshold, and it's been working fine ever since. Now one other question I have about these amps is with the display. We have several of these in use that have been running for years and the displays have faded so dim that I can barely read them. Would you happen to know if the displays themselves fade out over time, or if there's another problem like a low voltage causing them to go dim? Thanks again

[@treadmillrepair754]

@@TrevorsBench Hi, I have one CDI 1000 amplifier in my shop, something wrong happen with it. Burning the driver transistors, NPN and PNP, output transistors are OK, and everything looks good. Any idea? Best Regards.

[@MrProvinspoul]

The foam on top of the cooling fins, I'm pretty sure is there to stop the fins from "singing", some users just use a piece of tape, but since this amp has very large fins, they probably chose foam

[@GraeboProductions]

FOAM : to seal the chamber for air flow ? ; insulate them from the chassis ! , and/ or prevent rattles from the cover if something caved in the cover. Crown and QSC are notorious for having "live" heatsink...

[@DrAVRECEIVER]

Thank you

[@NoMoreRadioMyths]

Why not replace those resistors with a value that is close?

[@TrevorsBench]

The problem here is the close proximity of the resistors and cap. Changing the resistors won't make them dissipate any less heat but changing them to 2 watt would make them run slightly cooler. This would only help marginally (maybe) I do think this is a oversight of the designers at Harman. I don't understand why they would use such a specific value resistor and then run them to the limits of stress like that. They could have easily come up with a more robust solution

[@mattmoreira210]

​@@TrevorsBench You don't need to be an engineer to make such a half-assed amplifier design, I can tell you that much.

[@DrAVRECEIVER]

Somebody help me out to find the value of bunch of 2w resistors, in my amp colour are faded (located near 35v 220uf)

[@ethersecure2432]

Is the fact that you refer to volume as "amplitude" a giveaway that you're an engineer?

[@TrevorsBench]

Lol, no, but i did work with engineers all through my career. Maybe some of that rubbed off

[@ethersecure2432]

@@TrevorsBench fair enough, lol. Awesome content btw!

[@DrAVRECEIVER]

Model number is crown DSI 2000

[@jvchoer]

can you come to the netherlands? to make my amp

[@franciscojavierizquierdove8903]

Hola tengo un CDI2000 enciende el amplificador, pero el display color azul está apagado ayuda por favor

[@raymondanderson9494]

I would like someone to work on my crown straight line I am in Dallas can anyone recommend where I can take it

[@alx21i10]

Hi! I have the same amp,but i dont know why all my functions on display shows locked!Any advice how i can fix that?Thanks,you are doing very nice videos!

[@lacrossewieas2411]

Use audio architect and a printer cable to disable lockout

[@koteykini]

hi, 11:57 what did you replace the capacitor with, what is the capacity and voltage?

[@TrevorsBench]

Hi, Capacitor C196 is a 220uF 35v electrolytic. Use a cap rated at 105 degrees C if possible

[@kilgoredangertrout716]

Since it’s a known fault, it wouldn’t hurt to use the 105c like he said, I would consider using a slightly higher voltage cap as well, like a 220uf 50v cap. Cheers

[@g1981c]

pretty sure this isn't a class D amp otherwise why does it need those huge heatsinks for ... this seems very similar to my QSC PLX amp that has a switch mode supply and class H output stage ...

[@GraeboProductions]

yeah ! that amp is the install version of the XTi-2 which is a touring/mobile amp. Class H all day long. Would have been used in a movie theater, bar or nightclub. It being clean but worn out .... probably install in a air conditioned amp rack / equipment closet.. The XTi-2 are good amps. I rented a few with McCauley subs for a show....he should have replaced the resistors at minimum with the originals. I am sure crown sold/sells them. Bat shit ignorant to be putting his hands on those heat sinks. The foam is there for insulation. The heatsink are hot with voltage. Hey DUDE - RTFM before working on stuff.

[@boboso875]

Should have tested it before changing all of them mine doesn't power up at all

[@Ommusicsystembhimberazamgarh]

My amplifier crown cdi4000 automatically 4se 5 second shutdown no on amplifier .please the problem

[@soundtech3508]

I can repair,Where you from?

[@Ommusicsystembhimberazamgarh]

Live from up azamgarh

[@renecorrea8025]

Tengo un Crown CDI 1000 se bloqueó el panel frontal ayuda porfavor

[@TrevorsBench]

The user manual for this amplifier can be found online, you should get it if you haven't already. Try to connect the amp to a computer and use the System Architect software (a free download from www.harmanpro. com). You should then have full access

[@saratchetia2195]

my xti 4002 power on and automatically shutdown 4,5, sec .... what th prblm

[@amolmali329]

Sem my prblm

[@saratchetia2195]

@@amolmali329 ?

[@mattmoreira210]

13:31 you OBVIOUSLY don't need 48.7k resistors there. Whack some 47k ones in there and she'll be right. The "engineers" chose that rather exotic value out of pure idiocy.

[@DrAVRECEIVER]

SIR is that 41kohm Or 47kohm

[@anitacabello6020]

Me gustaría que subtitularan el vídeo en español

[@TrevorsBench]

I'll see what I can do for you

[@miguelmauricio2908]

APRENDE INGLÉS TODO QUIEREN PELADITO Y EN LA BOCA

[@gillanland]

This is Class-l amp, not class D.

[@valdiebsonmarcelino2218]

Brasil YES OK

[@Ommusicsystembhimberazamgarh]

Hindi mein boliye