Sony TA-F170 Stereo Amp - Speaker Protection Relay Replacement [Fixed] - Page 1
Forum section: electronics / repair

author: sean0118
author_rank: Frequent Contributor
timestamp: February 26, 2023, 06:55:04 am
content: 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 aMatsushita(Panasonic)JD2a-DC24VAJD4946. 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...

author: mariush
author_rank: Super Contributor
timestamp: February 26, 2023, 07:43:07 am
content: Digikey (and others ex mouser, newark/farnell) is full of relaysDigikey relays 24v-ish, dpst-no , over 2A :https://www.digikey.com/short/zvzzp9n5Seems 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 seehttps://www.digikey.com/en/products/detail/omron-electronics-inc-emc-div/G6C-2114P-US-DC24/105565May not look pretty but what would stop you from bending the leads a bit?

author: sean0118
author_rank: Frequent Contributor
timestamp: February 26, 2023, 08:01:17 am
content: Quote from: mariush on February 26, 2023, 07:43:07 amI was hoping to avoid that, but might need to, seems it's not a standard package anymore.

author: tooki
author_rank: Super Contributor
timestamp: February 26, 2023, 10:19:34 am
content: 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.

author: sean0118
author_rank: Frequent Contributor
timestamp: February 28, 2023, 05:12:24 am
content: I think theOmron G4W-2212P-US-TV5-HP-DC24might 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 ofOmron GC6is the polarised type, and opposite polarity to the PCB... Murphy's lawPanasonicDE2a-24Vis 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

author: sean0118
author_rank: Frequent Contributor
timestamp: March 05, 2023, 12:51:41 am
content: Okay thePanasonic DE2a-24Varrived.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.

author: sortons
author_rank: Newbie
timestamp: November 11, 2024, 04:50:32 pm
content: 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-24VSaludos