Mastech HY3010E-3: "slave" side not working

Thread Starter

Bradysdad

Joined Oct 28, 2023
5
Hello, all!

I just got a used Mastech HY3010E-3 and it appears to work fine in PARALLEL and SERIES modes but in INDEPENDENT mode, slave side does not function at all.

I do have the two pushbuttons popped all the way up to activate INDEPENDENT mode to no avail.

The free-standing 5V section works fine (4.89v on the meter).

Also, FWIW, I can't adjust the AMPS at all on either side, regardless of the mode.

I repair arcade games and pinballs as a hobby, so I'm hoping with some guidance or a schematic, I may be able to repair this.

UNLESS - it's not broken and I'm missing something. I have RTFM and there doesn't seem to be any mention of an overload reset procedure for this model and I have tried all the suggested settings (dials fully clock-wise, etc.). Does the slave side need a load to operate properly perhaps - no mention in manual either way.

TIA!
 
Check if a minimum load is required in independent mode.
Clean or check the mode selection buttons for proper contact.
Verify the current-limiting circuit components for issues.
Inspect internal fuses for damage.
Contact Mastech support for assistance or look for a schematic diagram online.
If unsure, seek help from a qualified technician.
 

Thread Starter

Bradysdad

Joined Oct 28, 2023
5
Check if a minimum load is required in independent mode.
Clean or check the mode selection buttons for proper contact.
Verify the current-limiting circuit components for issues.
Inspect internal fuses for damage.
Contact Mastech support for assistance or look for a schematic diagram online.
If unsure, seek help from a qualified technician.
1. Nothing mentioned in manual and placing under load illicits no change.
2. Working properly - confirmed with meter.
3. Tough to do with no schems.
4. IIRC, there was one fuse and it was intact, per meter.
5. Will reach out to Mastech and have searched high and low for schem online.

Thanks.
 

Thread Starter

Bradysdad

Joined Oct 28, 2023
5

Thread Starter

Bradysdad

Joined Oct 28, 2023
5
FWIW. . .

R204 and R203 were fried and Q202 and Q203 popped.

Replaced all and Q202 immediately popped again.

I assume the "2" series is the circuit for the SLAVE and the "1" series for the MASTER as they seem to be identical circuits.

So, something in the SLAVE circuit is popping the lid off Q202.

Traces show that connects to Q203 and to a couple of transformers on the main board as well. May try swapping out the identical circuit transformers to try and troubleshoot which one is bad.

Other suggestions welcome.
 
Top