Technics Graphic Equalizer won't power on

[lttnorth]

Just recently bought this Technics SH-8036 off eBay. The seller had it listed as working, however upon plugging it into the wall the darn thing wouldn't power up! I took it apart to see if there were any immediate signs of damage (blown caps, disconnected leads, etc), but I'm scratching my head here. I'm no expert by any means but I honestly can't see anything wrong with the board; still it refuses to power on. Posting some pics for any experts who might know what to look for.

I only paid 30 bucks for it, and the seller is even offering a refund, however I'm afraid the Post back to Canada is going to be too much and may not make this worth it in the end. Advice?

 

[SVI2004A]

Is there continuity on the power plug?

 

[redk9258]

Those two caps look like they have been quite hot. PVC shrinking back. No fuse?

 

[NAD80]

Ittnorth welcome to AK. Check the transformer primary and secondary windings for resistance. And open reading shows bad transformer. Check the bridge to see if it is shorted.

 

[Bob]

download the schematic and look for a fuse otherwise the above posters have good tips.

 

[Tom B]

Also check for cracks in the board, or on the foil, especially near the power transformer, as rough handling can cause small or large cracks in the board, especially where the screw holes are, as well as where the hevy transformer is mounted directly to the board.

 

[Binkman]

Seller should pay for re-shipping? So say to seller... do you really want this back? Soask for ? -100% refund back on your ppal..

Probable explanation is some gorilla dropped it or it fell off a shipping center belt line as 'Tom B' cites.

 

[SVI2004A]

What model xfmr?

Should be SLT****

Main pcb is strikingly like SH-8046

 

[lttnorth]

Is there continuity on the power plug?

I'm still digging around for my multi-meter but that'll be the first thing I check.

Ittnorth welcome to AK. Check the transformer primary and secondary windings for resistance. And open reading shows bad transformer. Check the bridge to see if it is shorted.

Thanks, will do.

Seller should pay for re-shipping? So say to seller... do you really want this back? Soask for ? -100% refund back on your ppal..

Probable explanation is some gorilla dropped it or it fell off a shipping center belt line as 'Tom B' cites.

The seller contacted me today and told me to just keep the thing, and he still gave me a refund. We both believe each other but nevertheless, it's still frustrating.

 

[NAD80]

Also check for broken solder joints. Where the lead has a ring around it (bad) as compared to a smooth solder flow around a lead on the pad. Could you post a pic of the front and back of the unit. Trying to match the unit to one I can find a SM for. (8038,8028,8044,8046 I can find.)

 

[SVI2004A]

8046 looks to use SUPK1100 pcb

This is why I specifically asker of Xfmr #

 

[Binkman]

yes get the dmm out. you/ll need it.

Pretty sure it's a prob. a simple solution from ac input transformer as noted by our illustrious posters. eg. cracked pcb. etc. noted. These are low v units and don't usually have fuses so they just conduct frequencies... agree sounds like a trace crack.

 

[lttnorth]

So I was finally able to revisit this. Checked continuity in the power lead and there were no breaks. Cord receives power when the unit is turned on but still nothing past that. Gonna have to just work backwards from here but it probably is something to do with the transformer.

 

[NAD80]

Measure both the primary (AC) side, secondary (Low voltage AC output) resistances, to find out if the windings are open. Also measure on the output side of D1 (+/-) to check that there is no short or open across the bridge.