Peavey VYPYR 15

[Valvehead]

I have a dead Vypvr 15 combo here. I get a thump when i turn it on, but no sound and NO lights . It does have about 8.4ac coming out of the power trans.

It has the TDA2040 chip , but i would think i would have lights even if its bad.

the fuse is good.

anyone been working on these yet ? common problems ?

also - is there a schematic to be had online ?

[Enzo]

Schematics for Peavey products are usually easiest to find at customer service at Peavey.

NO lights means either the logic has no power supply, or the logic has failed. Customer serviec can tell you the reinitialization procedure. ther are four buttons and you hold 1 and 4 or some combination while you power up. There are only a few combinations, so if it is not 1-4 or 1-3, keep trying combinations. or ask them. it might be all you need.

[Valvehead]

ok, i will call them. I tried a bunch of combination's, it didnt do anything.

[Enzo]

Then start by looking at powr supply. But if you are the original owner, why screw around? Take the unit in for warranty service.

[Valvehead]

i bought it broken ...just a little project


i did check a couple things , the output chip has 12v to it , and the other 3 (3 pin) chips on the ps board have 8-10v to them , (off the top of my head)

theres a ribbon going from the ps board to the dsp board. what kind of voltages should be going through that cable ? maybe that will tell me if the ps is sending out the proper amount

[Enzo]

I don't know, read the schematic.

[Valvehead]

Thats what im trying to do.


the connector i tested (on the ps board) just now isnt labeled. Its the 8 pin thats to the left of C3 on the Layout drawing. It goes to the dsp board .

From left to ight , top row first , i get 0v / 29v /5v / 0v , bottom row is 3.7v/ 8mv / 9.3v / 10v .

this doesnt make sense because they Layout drawing shows no connection to a few of those pins that have voltage.


ALSO- out of P1 , the connector going from the Dsp board to the encoder board, most of the pins have about 2V .

[Enzo]

The pictorial only shows the board traces on the one side. There are traces on the other side too.

Looking at page 2 of the power amp section, upper left, there is your 8 pin ribbon connector labelled.

SO for 0/29/5/0, to me the grounds are OK on the ends, the 29 is close enough to the 30 on the drawing, but your 5 ought to be more like 8. And according to the schemastic, your 3.7v/ 8mv / 9.3v / 10v ought to be more like 5/0/+12/-12

SO make sure R5 is not burnt open. And see if all your three terminal voltage regulators are working. If the voltages are not coming out of them, they won;t get to the ribbon either. Are the filter caps working? Unplug the ribbon cable - the amp circuits could be loading the power supply down.

[Valvehead]

U1 (3.7v /5v)

U3 (9.9v /10.5

U4 ( 9.2v/10.5v)

all the voltages im checking against the scem seem a little low , like 2 or 3v. This is on the ps board .


R5 tests 0.4 ohms and it has no voltage on either side of it. also shows 0.5 ohms on both sides to ground.

[Enzo]

Both sides of R5 ARE ground, by the way.

So what AC voltages are hitting the rectifiers? Set your meter to AC volts and remeasuer those DC supplies. This measures ripple. They should have essentially zero AC on them. if that 5VDC that measures 3.7VDC also measures like 2 or 3 VAC, then the filters are not happening.

Are you leaving out a polarity sign? There is +12 and -12. You are reporting only positive voltages.

[Valvehead]

yes, sorry i left out polarity.


heres what im getting =

across C10 16.6 vac

across C11 4.7vac

D4 cath end 10.2vdc

D7+D8 cath end 4.6vdc


across D8 cath and D9 neg 2.8vac

across D4 cath and D6 neg 8.2vac


if im not measuring the right spots let me know

[Enzo]

16VAC center tapped is 8vAC on a side. Pretty tough to rectify that and get 18VDC.

All those voltages are way low. Is this amp set up for 240VAC operation or something?

Alternatively, does the power transformer get real hot after being on a little while?

[Valvehead]

WOW....

it IS a 240V model !!!

i never looked !

right on the back - 240V

and the trans says 240v input on it .

man--this is strange . I bought it off ebay and it came from Missouri !

I guess i found the problem .... thanks for your time Enzo



So...after i get the US trans, will there be any changes to the power supply ?

[Enzo]

I doubt it, the seondary voltages should be the same for either.

[Valvehead]

Thanks again Enzo



(the new trans is only $19)