Kicker zr600 blowing fuses

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Ok so this amp has been sitting around for a while, basically when i turn the remote wire on it powers up but then blows all 3 internal 30A fuses immediately. ive done this twice now.

I dont know a great deal about the inner workings of the amp but i know how to use an iron and multimeter and know a bit about electrics.

Where should i start looking first as it appears theres a short in the power supply somewhere, maybe because the amp has been sitting for ages. because its an old school amp should be easier to work on.

also there are pics of the amp here: http://ampguts.realmofexcursion.com/Kicker_ZR600/


any help MUCH appreciated,
 
So I had a look and read pretty much everything on your site to do with amp repair (helpful). there are some that have item number RFG70N07 which are the power supply FETs i think, on the audio end there are TIP35C and some TIP36C as well.

there is no visible damage to the inside of the amp.

what tests can i run to determine which transistors are shorting if that is the case. I've read your section on testing transistors but don't I have to actually remove them from the board to do those?

Thanks again
 
The amp runs with 4 tip35c and 4 tip36c per channel. Theres a dead short between collector&emitter on one of the tip36c which is a PNP bipolar junction transistor.

There aren't any total shorts on any of the other transistors. Although i get some odd low readings like 22 ohms which shows between the outer legs on all the other transistors I suppose this might be because theyre in parallel with the defective one?

I take it i need to buy a few of these tip36c and once theyre fitted the amp should work?
 
If the meter tells you that you have 1 shorted output and it's still in the board, you also have at least 1 open emitter resistor.

You MUST replace all 4 of the TIP36s in that channel. I'd also recommend that you replace the TIP35Cs in that channel. If you have one open emitter resistor, you must replace all 4 that are connected to the TIP36s in that channel.

I'd recommend On-Semi brand replacements for the 35s and 36s.

The 22 ohms is the base-emitter resistor.

Generally, if you remove the shorted transistor, the amp will operate normally if there is no other damage. If you try this, clamp the transistors tightly to the heatsink before applying power. I'd recommend that you also insert a 15 amp fuse in the B+ line before applying power.
 
Oh and also i'm in the UK so I dont think on-semi can deliver to me, also I couldnt find any of the 36c/35c using their search function.

I found some on flea bay though have a look (they also do the 35c): http://cgi.ebay.co.uk/ws/eBayISAPI....m=330341432274&ssPageName=STRK:MEWA:IT&ih=014

they do 5 of them for a few quid less but I think i'll get 10 of each so I can cherry pick them for perfect matching. Just wondering if anyone had any opinions or alternative suggestions as I'm wary of buying fake parts, but this seller seems legit.

Thanks again for all your help, Perry
 
Hmm with Mouser I have to pay £12 international postage when i'm really only getting a few tiny bits which i'm not too keen on, when with the ebay listing the postage is free to the UK, and seems legit as its a high power seller with 100% feedback. I think i'll go with the ebay as I cant find many suppliers with these parts that will deliver cheap to the UK

as for the resistor I suppose anything which matched the one you recommend would be okay?
 
Using a 350w computer power supply to try and run it without the bad transistor, the amp goes into protection and the PSU trips and turns itself off immediately.

Although this maybe because of the very large capacitors causing the amp to draw huge current as soon as its connected I guess? the PSU is only rated 10.5 amps at 12V. 10A Fuse doesnt blow presumably because the circuit breaker in the PSU is much faster to cut the circuit
 
Set them all the way round like you said and same thing happens - psu trips and turns off. Also i hear a *click* from the audio end of the amp sounds a bit like two relays actuating at the same time.

No other output transistors seem to be damaged as the 36c and 35c all read 450ohm and 400 ohm respectively - across emitter and resistor. I get the same readings as before.

I get my car back from garage tomorrow so i'll run the same test properly in the car then.
 
WOW it works!!! :D :D

Turned bias all the way round like you said, took it out to test and the damn power light comes on and no blowing fuses and no protection!! And it was also fine when I turned the bias back to the correct place as well... hooked it up to some speakers and it played through both channels as well. Just took it out for a bit of a drive now to confirm as well, turned it real loud and no problems. :D I was getting worried something was majorly wrong and unrepairable... the amp cost me a fair bit when I got it.

Well I owe you lots of beers for that mate... I prolly would never have figured it out by myself. :)

Thanks a lot.
 
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