PHILIPS/ROVER R860 Sibilance - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

'LIVEWIRE?' · 2nd Nov 2018, 9:43 am

PH, you've just reminded me that there was a problem with the EEPROM's in one series of Philips Stereos 'back in the day', I recall replacing a few for the same reason you mention, but can't remember which model or series was involved. If the EEPROM in the OP's stereo is faulty in this way, a replacement will be difficult, if not impossible to source now, but the radio will still function, albeit with the need to retune to the station being listened to if & when power is turned off for even a short time. A failing EEPROM is, IMHO, unlikely to cause sibilance.

pichacker · 2nd Nov 2018, 10:08 am

True re the sibilance.

Slightly off topic but as for replacing the EEprom it would not be an issue as it's a common I2C 24C02 type that is used. You just need to copy the original EEProm to the new one. What happened was that the radio used to write the settings for channel in use, band etc as soon as you changed them. This resulted in a high read/write cycle occurance and wore out the EEprom. The result was that it retained a value and could not be updated. So for instance if you changed band to FM and switched off then on often you'd be back on a random AM station.

If it was one of the early DC751/DC752 variants then you'd have an ER1400 EARom which would be rocking horse doo doo to replace.

In my drawer to the right of me i have a black plastic ringed flywheel from a philips deck that has not split. Must be one of the few.

'LIVEWIRE?' · 2nd Nov 2018, 2:05 pm

At the time I worked in the trade, neither the firm for whom I worked, nor I had any means to copy data from one EEPROM to another. AS you say the DC751/752 series EEPROMs are now 'unobtanium'
Your comment on the Flywheeel, presumably from either a P1 or P6 deckj reminded me that I must have repaired many of those decks, using a repair kit supplied by Philips -still have a kit somewhere. I got this down to a fine art, such that I could dismantle, repair, reassemble and (briefly) test three DC751's (or other models) in an hour! Might take me an hour to do one now!!

TonyDuell · 2nd Nov 2018, 5:41 pm

As an aside, Littlediode list the ER1400. I am not surprised, I am pretty sure I got one from there for a Prestel set a couple of years ago.

So not quite in the 'hen's teeth' category yet.

Chris55000 · 4th Nov 2018, 12:59 am

Hi!

If anyone's really unlucky with a Philips car unit (22DC752, etc.,) using the ER1400 earom, there are circuits on the internet for easily–built programmers/programming interfaces that basically consist of level translators and an auxiliary –LT Vpp supply, and I think "Pony Prog" will support the timing routines for re–programming EAROMs, so an ER1400 duffy is not the end of the world yet if you can get one – I know because I researched this in connection with ancient Eurotherm temp. controllers that used this device!

Chris Williams

2nd Nov 2018, 9:43 am	#21
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: PHILIPS/ROVER R860 Sibilance PH, you've just reminded me that there was a problem with the EEPROM's in one series of Philips Stereos 'back in the day', I recall replacing a few for the same reason you mention, but can't remember which model or series was involved. If the EEPROM in the OP's stereo is faulty in this way, a replacement will be difficult, if not impossible to source now, but the radio will still function, albeit with the need to retune to the station being listened to if & when power is turned off for even a short time. A failing EEPROM is, IMHO, unlikely to cause sibilance.

2nd Nov 2018, 10:08 am	#22
pichacker Hexode Join Date: Aug 2008 Location: Essex, UK. Posts: 370	Re: PHILIPS/ROVER R860 Sibilance True re the sibilance. Slightly off topic but as for replacing the EEprom it would not be an issue as it's a common I2C 24C02 type that is used. You just need to copy the original EEProm to the new one. What happened was that the radio used to write the settings for channel in use, band etc as soon as you changed them. This resulted in a high read/write cycle occurance and wore out the EEprom. The result was that it retained a value and could not be updated. So for instance if you changed band to FM and switched off then on often you'd be back on a random AM station. If it was one of the early DC751/DC752 variants then you'd have an ER1400 EARom which would be rocking horse doo doo to replace. In my drawer to the right of me i have a black plastic ringed flywheel from a philips deck that has not split. Must be one of the few. __________________ 6.3v on my heaters is no longer enough to get me going in the morning!!

2nd Nov 2018, 2:05 pm	#23
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: PHILIPS/ROVER R860 Sibilance At the time I worked in the trade, neither the firm for whom I worked, nor I had any means to copy data from one EEPROM to another. AS you say the DC751/752 series EEPROMs are now 'unobtanium' Your comment on the Flywheeel, presumably from either a P1 or P6 deckj reminded me that I must have repaired many of those decks, using a repair kit supplied by Philips -still have a kit somewhere. I got this down to a fine art, such that I could dismantle, repair, reassemble and (briefly) test three DC751's (or other models) in an hour! Might take me an hour to do one now!!

2nd Nov 2018, 5:41 pm	#24
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: PHILIPS/ROVER R860 Sibilance As an aside, Littlediode list the ER1400. I am not surprised, I am pretty sure I got one from there for a Prestel set a couple of years ago. So not quite in the 'hen's teeth' category yet.

4th Nov 2018, 12:59 am	#25
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,870	Re: PHILIPS/ROVER R860 Sibilance Hi! If anyone's really unlucky with a Philips car unit (22DC752, etc.,) using the ER1400 earom, there are circuits on the internet for easily–built programmers/programming interfaces that basically consist of level translators and an auxiliary –LT Vpp supply, and I think "Pony Prog" will support the timing routines for re–programming EAROMs, so an ER1400 duffy is not the end of the world yet if you can get one – I know because I researched this in connection with ancient Eurotherm temp. controllers that used this device! Chris Williams __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!