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david covino #20746 Good morning, all.? I need your help.? My DX7 is one of those from Japan with the lamp cord power cord.? Recently, I've received this display and figured the battery was bad, so I changed it out, and reloaded the sounds from the cartridge to internal memory.? My problem is that the memory does hold the sounds for more than maybe 10 minutes, and internal memory reads as you see here, and it doesn't emanate any sound.? Strangely, in cartridge mode, all sounds are normal and they work fine. Has anyone seen this before and have any suggestions?? Battery voltage reads 4.6 volts with a new battery.? (As I recall, these models normally read more than the 3.3 volts for the CR2032) Thanks very much in advance! Kind regards,? L. David Covino? toggle quoted message Show quoted text -----Original Message----- From: David Covino <ldcbox@...> To: ldcovino@... <ldcovino@...> Sent: Tue, Jun 29, 2021 10:02 am Subject: Fwd: kB -----Original Message----- From: DAVID COVINO <ldcbox@...> To: ldcbox@... Sent: Tue, Jun 29, 2021 9:58 am Subject: kB IMG_4531.JPG IMG_4530.JPG IMG_4529.JPG
charles All Messages By This Member #20747 re cap your power supply , or check voltages at main and follow first
Bruce Wahler #20748 开云体育 Hi David, I'm not a DX7 owner (TX802 here), but here are some general comments: The battery is 3.1-3.3 volts.? If you are reading 4.6V, and you are certain that you are reading only the voltage across the battery, it sounds like the power is on.? You want to read the battery with the power off.? It should read 3.{something}. and the voltage going to the memory chips should be something around 2.7V, because of a blocking diode in the battery path. If the battery is actually reading 4.6V when power is on, I suspect that the blocking diode has shorted, causing the 5V power to feed the battery.? This is not a good situation for the battery, as it is attempting to take a charge.? Best case, the battery will be damaged over time.? Worst case, it could explode! Regards, -BW Bruce Wahler Halfmoon-Switch.com? bw@... 978.597.7008 PLEASE NOTE: ?The AshbySolutions.com domain will be closed soon. ?Please use the new (wahler.us) email for all future correspondence. ?Thank you for your understanding. ? ? On 6/29/2021 10:13 AM, david covino via groups.io wrote: toggle quoted message Show quoted text Good morning, all.? I need your help.? My DX7 is one of those from Japan with the lamp cord power cord.? Recently, I've received this display and figured the battery was bad, so I changed it out, and reloaded the sounds from the cartridge to internal memory.? My problem is that the memory does hold the sounds for more than maybe 10 minutes, and internal memory reads as you see here, and it doesn't emanate any sound.? Strangely, in cartridge mode, all sounds are normal and they work fine. Has anyone seen this before and have any suggestions?? Battery voltage reads 4.6 volts with a new battery.? (As I recall, these models normally read more than the 3.3 volts for the CR2032) Thanks very much in advance! Kind regards,? L. David Covino? -----Original Message----- From: David Covino <ldcbox@...> To: ldcovino@... <ldcovino@...> Sent: Tue, Jun 29, 2021 10:02 am Subject: Fwd: kB -----Original Message----- From: DAVID COVINO <ldcbox@...> To: ldcbox@... Sent: Tue, Jun 29, 2021 9:58 am Subject: kB
grantpbt All Messages By This Member #20749 There are several elements to the battery that need to be correct. Obviously the battery itself must be good and properly connected, then there is the germanium diode which you can test with most DMM's (Digital Multimeter ... not expensive, buy one if you plan to work on your gear), then there is a jumper on the bottom of the board (it can become unsoldered). You will need to verify the battery voltage right on the RAM ICs with the unit powered off to know if the correct voltage (around 2.5v to 3v) is appearing on the RAM. I wouldn't go by just the built-in battery voltage reading menu. GB toggle quoted message Show quoted text On 6/29/2021 7:13 AM, david covino via groups.io wrote: Good morning, all.? I need your help.? My DX7 is one of those from Japan with the lamp cord power cord.? Recently, I've received this display and figured the battery was bad, so I changed it out, and reloaded the sounds from the cartridge to internal memory.? My problem is that the memory does hold the sounds for more than maybe 10 minutes, and internal memory reads as you see here, and it doesn't emanate any sound. Strangely, in cartridge mode, all sounds are normal and they work fine. Has anyone seen this before and have any suggestions?? Battery voltage reads 4.6 volts with a new battery.? (As I recall, these models normally read more than the 3.3 volts for the CR2032) Thanks very much in advance! Kind regards, L. David Covino //___^ -----Original Message----- From: David Covino <ldcbox@...> To: ldcovino@... <ldcovino@...> Sent: Tue, Jun 29, 2021 10:02 am Subject: Fwd: kB -----Original Message----- From: DAVID COVINO <ldcbox@...> To: ldcbox@... Sent: Tue, Jun 29, 2021 9:58 am Subject: kB
Ant Goffart All Messages By This Member #20750 I had a similar problem with mine. The memory would get corrupted when switched off, even with a fresh battery. In the end I found the fault was ZD1 (a 6.2V Zener diode) on the power supply board. This is used in the circuit that detects the power being switched off and puts the RAM into a safe reset state before the main power goes off. Without this happening properly the RAM can get spurious writes as the unit powers down. Hope this might help.

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