harman kardon avr 3700

[Jjosip]

Re: harman kardon avr 3700

Thanks for info. Greatly appreciate you quick response. if the only difference btw 370 and 3700 is the input voltage - PWM controller should be the same.
So, will look up for 370 schematics, at least it will give me some clues what could cause the explosion and what kind consequences could be.
Wondering, if any reliable source of OB2358 known to this forum? Looks like Ebay only the option. But, knowing quality of "old new stock" from China, I am quite hesitant to go that route.

I really think they're the same. You don't have to worry about parts from China. At least you know you're buying originals 🙂 It would be Weird if you bought it from USA or Germany. Here is a link to AVR370 service manual if you didn't found it. Try to compare parts arround IC91.

[tibimakai]

Re: harman kardon avr 3700

AVR1700, uses the same IC91 chip. I'm fighting with that power supply myself. I have purchased these chips, from Aliexpress(twice already).
We can't get a 5V standby, on the other side of the transformer.
If it would be me, I would start measuring all the semiconductors, on the amp board.

[Pjstone]

Re: harman kardon avr 3700

What i have decided to try and do is use it as a pre-amp only for stereo music. i will unplug the power amp connector and see if everything still works good that way i can still use it and not put another fetchin dime into it.

[tibimakai]

Re: harman kardon avr 3700

Did you try replacing the standby transformer? It is like $7-8 from HK.

[Pjstone]

Re: harman kardon avr 3700

i have not tried that yet. Which part is that on the board?

BTW it works without issue with the amp board disconnected.

[tibimakai]

Re: harman kardon avr 3700

I'm at work right now and I had the AVR1700, but I believe that, it is the smallest transformer.

[Pjstone]

Re: harman kardon avr 3700

ok thank you. i bought a 1700 as a parts unit that the power supply works but the ethernet does not work and it goes into program mode ( i think thats what it is ) if i leave it on. i can take the part out of that unit.

[Ri5ux]

Re: harman kardon avr 3700

If anyone still needs help repairing the AVR 3700 / 370 or AVR 2700 / 270, I've created a guide on how to fix the power on issue. I've fixed two of these units already. It's quite a simple repair actually. Here's the video: https://www.youtube.com/watch?v=q75koBaNjU4