Yamaha HTA-5630RDS Amplifier dead

[roadrash]

Belongs to my son and he just says it stopped turning on. Any help greatly appreciated. Theres 240v in and fuse is ok but no power anywhere else.

[roadrash]

The first picture wasnt very good so here is another. I cant seem to meaeasure any voltage anywhere other than the 240v mains input on the small pcb top left. I checked the 470uf cap on there and it is ok. There is no voltage going to the transformer below it on the blue and grey wires.
a bit of a mystery.

[roadrash]

1st image has got rotated 90 degrees to the right so my reference to top left is now top right.

[R_J]

How about checking some voltages... do you have standby voltage? I will give you a hint, it should be across C681, that 470µf capacitor.

[roadrash]

How about checking some voltages... do you have standby voltage? I will give you a hint, it should be across C681, that 470µf capacitor.

Thanks very much . Getting 50v across C681. I did check this cap and its within tolerance. I popped the cover off the relay and there is voltage there and manually moving the points gets a tiny spark.

[R_J]

If you are getting 50V across C681 either there is something seriously wrong with that standby circuit or your meter is bad. You should have around 14 vdc across C681

Are you sure about that model number? Could it be HTR-5630RDS

[roadrash]

If you are getting 50V across C681 either there is something seriously wrong with that standby circuit or your meter is bad. You should have around 14 vdc across C681

Are you sure about that model number? Could it be HTR-5630RDS

Yes your right its a typo sorry its HTR-630RDS.
i was meassuring the voltage across the cap with the 3 pin ribbon cable disconnected because its so short i couldn't find a safe way to turn the board upside down when it was live to measure the voltage. I just got the Mrs to hold it for me and with the 3 pin ribbon cable connected there is no voltage showing across that cap.

[R_J]

That is the standby power supply, on your model the standby consists of T681 transformer, bridge diodes (D6683,684,686,687) I would check the resistance of the transformer, I suspect the primary is open.
Components in yellow are not in your model.

[roadrash]

That is the standby power supply, on your model the standby consists of T681 transformer, bridge diodes (D6683,684,686,687) I would check the resistance of the transformer, I suspect the primary is open.
Components in yellow are not in your model.

Think your right about the little transformer as can only get a reading on 2 contacts on one side of the transformer and nothing on any other pair of contacts. Could you possibly point to a suitable replacement on ebay or rs etc.

[roadrash]

Typed these numbers into google and nothing found.

[R_J]

This is the part number from the manual for T681 XW608A00 TRANS.PWR TKABGL (British model) A search on the internet found a few listings
If you can find a small (non pc mount) transformer with your country primary voltage and a secondary voltage of around 12~13VAC you could likely wire it in and mount it inside somewhere.

[roadrash]

This is the part number from the manual for T681 XW608A00 TRANS.PWR TKABGL (British model) A search on the internet found a few listings
If you can find a small (non pc mount) transformer with your country primary voltage and a secondary voltage of around 12~13VAC you could likely wire it in and mount it inside somewhere.

would this one do?

https://fixpart.co.uk/product/yamaha...A0NjQ.#reviews

[roadrash]

That is the standby power supply, on your model the standby consists of T681 transformer, bridge diodes (D6683,684,686,687) I would check the resistance of the transformer, I suspect the primary is open.
Components in yellow are not in your model.

Well i found a new transformer and fitted it but sadly it still doesn't turn on any more things to check?

[roadrash]

I cant figure this one out at all. Its beyond my abilities to diagnose and work out where the fault lies. Ive checked most everything on the standby power supply board including the transistor, and all diodes plus I replaced the elecro cap and the transformer which I had to get from Germany and cost me £20. The fault must be elsewhere.

[R_J]

It is a simple transformer; do you have line voltage on the primary? do you have 14vAC on the secondary? What is the resistance of the primary winding and the (center tapped) secondary ?

[roadrash]

It is a simple transformer; do you have line voltage on the primary? do you have 14vAC on the secondary? What is the resistance of the primary winding and the (centre tapped) secondary ?

Thanks for the reply RJ. Dont know if I am taking measurements from the wrong place. On the transformer there are 2 contacts on one side and 4 on the other. I am not getting any voltage reading on the single pair of contacts which I thought were the primary ones. I hooked the transformer up to my component tester and look at the photos to see the results I got. These were the only pairs of contacts that gave a resistance reading.