Sony TA-F170 Stereo Amp - Speaker Protection Relay Replacement [Fixed]

[sean0118]

Hi all,

I have this Sony TA-F170 I'm repairing, has one channel which keeps going dead until the volume is turned up. I pulled the speaker protection relay, it looks okay and I tried to clean it with Deoxit, but one of the switches seems to be intermittent, was testing at 2A and would sometimes be high impedance.

The original relay is a Matsushita (Panasonic) JD2a-DC24V AJD4946. Can't find a datasheet but basically it's DPST-NO, 5A 125VAC / 250VAC / 30VDC. Coil is 24V DC and 700Ohms. Package length 25mm, width 15mm, height 25mm (see attachment for footprint dimensions). It's driven by an NEC C1237HA protection IC (80mA max drive current)

I could attempt to clean it more but I'd really just prefer to replace it... the only problem is I can't find a suitable replacement relay. I've seen Omron G4W-2212P-US-TV5-HP-DC24 recommend, pin pitch is correct but package is too big, in this amp there's other components right next to the relay it will clash with...

Can anyone suggest a good replacement part? I assumed it would be a standard footprint... but I can't find anything suitable...   

[mariush]

Digikey (and others ex mouser, newark/farnell) is full of relays

Digikey relays 24v-ish, dpst-no , over 2A : https://www.digikey.com/short/zvzzp9n5

Seems like a lot of them are shorter  as in  [ 10.16 mm ] [ 7.62 mm ]   but the width between the pins is 10.16mm and the total width of the package is 15 mm.
For example see https://www.digikey.com/en/products/detail/omron-electronics-inc-emc-div/G6C-2114P-US-DC24/105565
May not look pretty but what would stop you from bending the leads a bit?

[sean0118]

May not look pretty but what would stop you from bending the leads a bit?

I was hoping to avoid that, but might need to, seems it's not a standard package anymore.

[tooki]

Looking at the PCB layout in the service manual, it looks like one option would be to use the Omron GC6 suggested by mariush, but to drill new holes (red in screenshot) for the coil pins, then just jumper them over.

Or you could use some veroboard to build an interposer board to adapt the footprint, if you don’t want to alter the original PCB. Or go super fancy and design a real PCB to let you convert a modern THT or SMD relay into a substitute.

[sean0118]

I think the Omron G4W-2212P-US-TV5-HP-DC24 might actually fit better than I thought initially, I made a template of its footprint out of paper, seems to clear the connector, but still covers D702...   

Unfortunately the coil of Omron GC6 is the polarised type, and opposite polarity to the PCB... Murphy's law 

Panasonic DE2a-24V is another polarised relay, but polarity matches the PCB. Footprint is close, width of pin pitch is off (7.62mm), but I think I can make it work...


I'll give it a go and report back 

[sean0118]

Okay the Panasonic DE2a-24V arrived.

It did fit, but only just, the pins are short and after bending they only just fitted through the PCB enough to solder...

But the amp does work reliably now, so seems to be all fixed. 

[sortons]

Hola buscando he visto este post y tengo exactamente el mismo problema con un amplificador sony ta-fa411, cuando quiere un altavoz deja de sonar o suena poco y si subo el volumen empieza a sonar otra vez.
Creo que está mal el relé que activa los altavoces y tenía pensado poner el Omron G4W-2212P-US-TV5-HP-DC24, que en mi amplificador si cabe, pero he visto que decís que la bobina va polarizada??
Aunque soy poco experto en electrónica, he leido el datasheed del omron y no encuentro nada donde diga que la bobina tiene polarización.
Me lo podeis confirmar?
En otro caso tendría que buscar otro alternativo.
Te funciona bien con el Panasonic DE2a-24V

Saludos