Scratched cocktail glass

Retroman839 · Sep 6, 2026

Fuse is short …

I didn’t expect this to be this simple,
Was expecting to remove transistors .
Also 2 spare fuses I found in corner of cab are what’s required .

I wonder as +5v requires a 6 amp fuse
And the other 3 rails only use 1A if the fuses left in cab will be all 1A only or 1 & 6amp . Will find out Tomo

Will test it tomo with replacement fuses hopefully . If the spares ones ain’t blown as well

eliotcole · Sep 7, 2026

Got a box of them things somewhere, mate ... can bring up (but you can likely Amz them quicker) if you need.

Retroman839 said:
View attachment 64132

Fuse is short …

View attachment 64134

I didn’t expect this to be this simple,
Was expecting to remove transistors .
Also 2 spare fuses I found in corner of cab are what’s required .

I wonder as +5v requires a 6 amp fuse
And the other 3 rails only use 1A if the fuses left in cab will be all 1A only or 1 & 6amp . Will find out Tomo

View attachment 64133

Will test it tomo with replacement fuses hopefully . If the spares ones ain’t blown as well

Retroman839 · Sep 7, 2026

Scratching my head on how to connect my 100v step down to this ….to this psu

eliotcole · Sep 7, 2026

Top right, no?

Retroman839 · Sep 7, 2026

You mean the missing fuse ?
no ..
My issue now is I don’t know how to wire this thing up to power .

Brain fart !

I will use a stepdown type I use for the cabs or consoles ..

2 prong usa type ..

But my iso step down has 2 taps to form the 100v and it total spun my head !!

Retroman839 · Sep 8, 2026

Right ok back to this faulty psu …

After trying to wire this thing up tired enough to sleep standing
Up I went to bed .

Now is the next day and I’m slightly more awake .

Got this wired up ..

Here are my results
On the +5v that was dead in the cab I have

7.99v+

On the 5v+ that worked fine in the cab
I have

At the fuse for the outlet ….
Nothing ?

At the -5v that did nothing in the cab
I have

-10.50v

And last of all -12

-17.68

voltages with out fuses occupying the holders
Is
For the +5v
Nearest the caps I get nothing

+5v opposite side of fuse holder I get a good -5v
Here

-5v without fuse I get
-5.14v here

Then -16
Opposite side

So basically it’s screwy

Retroman839 · Sep 8, 2026

So off that tap of
T2 I get a great +5v and the +5v adjust pot works great to adjust it ….
😊👍…

So between the tap and my fuse something ain’t right ..
Will check schimatic

Retroman839 · Sep 8, 2026

My grounds on the output pins are reading -4.7v

That’s pretty large ground plane ..
And it’s at -4.7v?

Do I have a short ground to my -5v?

Retroman839 · Sep 8, 2026

This resister is the warmest component in the board at 45•c
May well be normal .

Retroman839 · Sep 8, 2026

All my 6 ground pins read 450 ohms to the -5v …

And buzz for a split second everytime I make contact ..

So I guess I have a failing decoupling cap possibly
Small caps

Retroman839 · Sep 8, 2026

This C19 right next to the -5v
Looks sheepish

Retroman839 · Sep 8, 2026

Changed c19
I now get perfect +5 and potentiometer adjusts the +5 lovely but it’s at the +12 location 🤪

Retroman839 · Sep 10, 2026

This High speed , high voltage switcher
I Shorted last night .😳
So 5 on way .

I removed a tantalum cap on the +5v line as these are prone .

Once removed .. no change on my voltage issue but a transistor started to click /tick faster or not at all depending on how I manipulated the 5v pot .

As this tant seems to bridge the 5v line and ground plane I thought this could be what’s causing my 4,5v on my grounds .. if it had failed

But I didn’t .