LaserDisc Database

[CLD-M301] No Power On!
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Author:  percy_u [ 26 Aug 2022, 22:54 ]
Post subject:  [CLD-M301] No Power On!

Good Afternoon friends from LD Database.

This time I rescue from junk a Pioneer CDL-M301 with power on failure, the only information I got from the seller, is that the unit doesn't turn on.

So I bought this LD player as a repair project, hope you can help me with some of the issues this LD is having.

1.- As you can see in the pictures no capacitors look bad or blow.
2. The 2 fuses are ok, and continuity is proper.
3.- The input cable brings 110v.

The issues I got so far:

1.- after been connect to a 110v source, the unit won't turn on.
2.- the voltage I got on the fuses is 0 volts. so I'm assuming the problem is with the power transformer.
I have not been able to find the service manual for this unit.
File comment: PB1
PB1.jpg [ 264.75 KiB | Viewed 418 times ]

File comment: PB3
PB3.jpg [ 349.99 KiB | Viewed 418 times ]

File comment: PB4
PB4.jpg [ 299.56 KiB | Viewed 418 times ]

File comment: PB5
PB5.jpg [ 277.12 KiB | Viewed 418 times ]

3.- as you can see in these pictures only 2 of the pins are welded, is this correct?
Can you tell me which are the right voltages for the pins in the transformer?
File comment: PB8
PB8.jpg [ 124.1 KiB | Viewed 418 times ]

Thanks, again for your answers and all your help.

Greetings from Peru.

Author:  cplusplus [ 30 Aug 2022, 03:23 ]
Post subject:  Re: [CLD-M301] No Power On!

Is that PCB burn-in where the AC cord comes in?

Check all secondary legs for voltage. If there is none, check primary legs indicated by the two arrows. The other legs should not be connected. If you have voltage there, unplug it and check continuity from the arrow on the right in the photo to the leg next to it with no solder mask. That should show continuity. If it does not, check the additional leg on the end.

If there is no continuity to one of the legs with no solder mask and there is primary voltage with no secondary, I'd assume the thermal fuse has melted. The safest check for that is to remove the transformer and jump the leg and see if you get secondary voltage. If so, you need to then find out why the fuse melted in the first place.

Author:  percy_u [ 04 Sep 2022, 18:26 ]
Post subject:  Re: [CLD-M301] No Power On!

Hello CplusPlus, good morning, thank you for your kind response and help again.

I did the tests on the transformer, and here is what I found.

1.- Is that PCB burn-in where the AC cord comes in?
Well looks kind of dark there, but as far as I can check the 114 volts are detected in the input ac cord.

2.- With the transformer on board, I got the next continuity results.
File comment: On board 1
1662309395394.jpg [ 195.4 KiB | Viewed 368 times ]

Primary Legs
a) Primary legs mark in red, does not have continuity.
b) Primary section shows continuity between the first leg mark with the arrow from the left of the pic, with the one mark in orange, is this correct?
c) The input voltage of the 2 red arrow marks is correct,114v as the input cable.
For secondary legs, I got the next results.

d) the green ones show continuity between them as pairs.
e) the mark with orange shows continuity between all of them.

With Power cable connected

1.- for both primary legs, I got 114 volts.

2.- for secondary legs, this is what I got:
- First 2 green legs got between 0.2 and 0.4
- Next 2 green shows between 2.8 to 0.5
the voltage change and jump between those values.

- Between the orange ones mark with 1 and 3, show 5.6, and then drop to 0.
- Between the ones marked with 1 to 5, I got 9.2 to 0, when the voltage drop never came back.
- Between 3 to 5, shows 4.9 to 0, also the voltage is random.

I took out the transformer and got the next result of continuity.

For Primary legs.
File comment: T1
1662309395372.jpg [ 179.72 KiB | Viewed 368 times ]

a) there is continuity only between legs 2 and 6 shown in the picture( the same result that I got on board)


For secondary legs.

File comment: t2
1662309395361.jpg [ 154.8 KiB | Viewed 368 times ]

a) I got continuity between legs mark in orange, 9-10, 11-12(this happens also with the transformer on board)
b) Also between the 14-17 mark legs, but no more continuity with the other ones, this is different from the first test on board, is that normal?


Can I connect the transformer direct to 114 volts? do I need to use any kind of protection device for the transformer, I want to see if I got any kind of voltage from the secondary legs.

When you tell me about the thermal fuse, this is inside the transformer?

Thanks again CPlusPlus for all your help, I will wait for your kind response to do the next tests.

:clap: :clap: :clap: :clap:

Author:  cplusplus [ 06 Sep 2022, 16:20 ]
Post subject:  Re: [CLD-M301] No Power On!

percy_u wrote:
do I need to use any kind of protection device for the transformer, I want to see if I got any kind of voltage from the secondary legs.

When you tell me about the thermal fuse, this is inside the transformer?

You need protection for yourself, but there is a lot of information out there on how to test transformers.

A lot of the schematics around this era show the fuse connects primary leg 5 to 6. You can see what are likely the legs of it in your photo. You probably will not be able to replace it since it is within the transformer, and jumping the fuse is a fire hazard.

Assuming a thermal fuse melted, you need to find out what caused it.

Author:  percy_u [ 07 Sep 2022, 04:02 ]
Post subject:  Re: [CLD-M301] No Power On!

Good Night CPlusPlus, well know that the Transformer is not working properly and the fuse is melted.

Can you give me some advice to replace it? the reason this happened should be that the unit was connected to 220v, this is the voltage here in Peru, and the unit is 110v.

I bought it as is, so I think that was the problem.

Is there a way to replace that transformer, do you know the voltages for the secondary legs? , I am not sure if the transformer can be fixed in any way.

Thanks for your answer and help.

greetings from Peru.

Author:  cplusplus [ 13 Sep 2022, 14:36 ]
Post subject:  Re: [CLD-M301] No Power On!

You would need to replace the transformer, but given that you would still need to fix the secondary, you are better off buying an entirely new supply. I will check if I have a similar one and measure voltages.

Author:  percy_u [ 16 Sep 2022, 14:57 ]
Post subject:  Re: [CLD-M301] No Power On!

Thanks CPlusPlus, that voltage information, will help me a lot.

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