Electrohome G07 B+ Light Bulb Test

[@Chrispehl]

I got a lot out of this. I appreciate you walking through using a light bulb to test.

[@jacklick]

Glad it helped. Good luck on your repairs!

[@waynegram8907]

How are you connecting the light bulb in series when you're connecting the light bulb in parallel it looks like there is no connection break to put the light bulb in series.

[@jacklick]

Lifting jumper w908 breaks the b+ power rail from rest of chassis. The bulb is then connected to the lifted w908 and to another part of chassis, effectively putting the bulb in ckt on the b+.

[@waynegram8907]

@@jacklick Does all various types of arcade monitors have a Jumper to break the B+ power rail from the rest of the chassis?

[@jacklick]

@@waynegram8907 I have only done this on one other chassis and want to guess that they likely do. However, like in this case, the jumpers are not always documented on the schematic, so it may require tracing the B+ line out from the power transistor, removing other stuff, etc.

[@equinoxshadow7190]

@@waynegram8907 I am working on a couple of WG K4900s, there is one jumper at the top of the pcb near the B+ Filter cap.

[@sideburn]

Yikes! I’ve been testing my board onthe bench without an isolation transformer. How is it not fried?!

[@jacklick]

if you didn't hook mains earth ground to the chassis it will likely be fine but often, inside a cabinet, the chassis frame is connected to earther gnd via a logic gnd and you will blow stuff up. Just always use a isolation transformer when working on monitors. It is for safety.

[@sideburn]

@@jacklick ahha now that makes sense! Thank you. I think it’s fixed. The board has been a bit of a nightmare. Cap kit, transistors, and flyback all replaced and it was still DOA. Found a bad trace and then it came up but with vertical collapse. Found another bad trace and now fingers crossed it is fixed. All components are testing good that I have checked. Problem is the machine is 200 miles away so there’s big delays between verifying if it is fixed or not.

[@jacklick]

@@sideburn fingers crossed for ya then. Good luck.

[@sideburn]

@@jacklick thank you. Should know in hopefully not too distance future. I’m anxious to find out!

[@irenatonney8436]

excellent

[@Music32ist]

Very Big HELP Thank You !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@jacklick]

Glad it helped. Thanks for the comment.

[@bdbusslowmotion]

Super