User Profile

maleksa started a topic Help to identify chips on Sony SRS-XB43

in Troubleshooting Audio Equipment

02-10-2025, 10:08 PM
Help to identify chips on Sony SRS-XB43

My Sony SRS-XB43 won’t turn on, won’t charge (no LED light when plugged in to USB charger) and won’t run on batteries. I tried changing batteries but no luck.

I am trying to figure out the cause of the problem and I need help to identify two (2) ICs, which are U4 (with marking CKUCFA) and U6 (markings [U]MPMS9[/U]428A643). I have attached a picture.

Appreciate any help or pointers.My Sony SRS-XB43 won’t turn on, won’t charge (no LED light when plugged in to USB charger) and won’t run on batteries. I tried changing batteries but no luck.

I am trying...

See more | Go to post
maleksa started a topic Yamaha MOX8 boot freeze and distorted sound

in Troubleshooting Audio Equipment

11-07-2024, 03:28 AM
Yamaha MOX8 boot freeze and distorted sound

My Yamaha MOX8 synthesizer recently developed two issues.

Firstly, after booting up, it operates as normal. However, after about 5 minutes, the sound starts to get distorted (broken up screeching sound) almost like putting it through a guitar distortion pedal. After a while, the distorted sounds will go away for a while and comes back. At times, the synthesizer will also freeze I need to power off and on again.

Secondly, when powering off and on again, there will be times where the synthesizer will freeze during the boot sequence (freezes at the MOX8 Opening Screen),...

See more | Go to post
maleksa replied to Korg Kross2 Service Manual and LCD pinout

in Troubleshooting Audio Equipment

10-13-2024, 07:56 PM
Thanks. Here are some pics of the original broken LCD. Hoe it helps.
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"IMG_4425.jpg","data-attachmentid":3483131}[/ATTACH]...

See more | Go to post
Leave a comment:
maleksa started a topic Korg Kross2 Service Manual and LCD pinout

in Troubleshooting Audio Equipment

10-11-2024, 05:54 AM
Korg Kross2 Service Manual and LCD pinout

The LCD on my Korg KROSS2 keyboard is cracked and needs to be replaced.

However, the cost of a replacement LCD is almost the same as the price of a second hand Korg KROSS!

Does anyone have a copy of Korg KROSS2 Service Manual? I want to see the PINOUT for the LCD connection. Perhaps I can find a compatible LCD screen and not have to spend a fortune on an original replacement LCD.

From what I can gather, the LCD screen is a COG with serial interface (SPI). Is there any way I can ascertain (perhaps with the use of a multimeter or oscilloscope) the PINOUT by...

See more | Go to post
maleksa started a topic Roland Fantom XR. Help with LCD screen pinouts

in General Electronics Technical Discussion

06-03-2024, 08:27 PM
Roland Fantom XR. Help with LCD screen pinouts

The LCD screen on my Roland Fantom XR rack synthesizer has gone blank. I managed to get the schematics for the connection to the LCD.

The standard LCD has D0 to D7 pinouts (in addition to the normal VDD, VSS, CS, RES, RW, EN etc).

Can someone help me to identify what V1 to VR is for? Also how does VR work?

Any help is truly much appreciated....

See more | Go to post
maleksa started a topic Zoom R16 help to identify ICs

in Troubleshooting Audio Equipment

05-02-2024, 05:43 PM
Zoom R16 help to identify ICs

My Zoom R16 would not turn on. I checked for voltage rails and I found that 2 out of the 3 inductors had voltages.

L19 read 3.3v
L10 read 4.5v
L11 had no voltage readings

I need help in identifying IC10 which could be the problem. Really appreciate any help on this.
...

See more | Go to post
maleksa started a topic HP Elitebook 1030 G3 power on settings

in Troubleshooting Laptops, Tablets, and Mobile Devices

01-09-2024, 11:54 PM
HP Elitebook 1030 G3 power on settings

My HP Elitebook 1030 G3 will not turn on unless I disconnect the battery and reconnect it (and press the power on button). After shutting down, I have to disconnect the battery and reconnect it again to start up via the power button.

I went to the BIOS and enabled turn on when lid opens. So everytime I want to turn on the laptop, I just open the lid.

So what are the settings that I need to change to enable the power button?...

See more | Go to post
maleksa replied to Roland JV-90 keyboard

in Troubleshooting Audio Equipment

01-09-2024, 09:36 PM
Thanks for all your pointers and feedback.

Just to update everyone, I downloaded the Roland JV-90 service manual which had the schematics. I did the following
1. I measured the XRES voltage at the power board and at all the ICs (that receives the XRES voltages) on the mainboard
2. I measured the 5V at the power board and at all the ICs on the mainboard
3. I also checked the capacitors to ground at all the XRES and 5V above (to check that they are not shorted)

After doing the above, the JV-90 worked perfectly. I also left it on for about 6 hours and there...

See more | Go to post
Leave a comment:
maleksa replied to Yamaha SY85 power board 220v or 110v?

in Troubleshooting Power Supplies and Power Supply Design

07-05-2023, 11:27 PM
Re: Yamaha SY85 power board 220v or 110v?

No R3 is not fitted. I have also got confirmation from another Yamaha SY85 owner that my keyboard model is for 110v AC....

See more | Go to post
Leave a comment:
maleksa replied to Yamaha SY85 power board 220v or 110v?

in Troubleshooting Power Supplies and Power Supply Design

07-05-2023, 11:26 PM
Re: Yamaha SY85 power board 220v or 110v?

Yes it is rated at 200v. You are right, the power supply is for 110v AC....

See more | Go to post
Leave a comment:
maleksa started a topic Yamaha SY85 power board 220v or 110v?

in Troubleshooting Power Supplies and Power Supply Design

07-01-2023, 08:49 PM
Yamaha SY85 power board 220v or 110v?

I need help to ascertain if the power supply on my Yamaha SY85 keyboard is 110v or 220v or both.

I have attached the schematics below....

See more | Go to post
maleksa started a topic Roland JV-90 keyboard

in Troubleshooting Audio Equipment

06-26-2023, 11:29 PM
Roland JV-90 keyboard

I have a Roland JV-90 keyboard.

When I switch it on from cold it works perfectly. However, after a few minutes it starts to act strangely. The LCD screen shows garbage, the LED lights starts to blink randomly and the sound that comes out are intermittent.

I notice that the main IC (Roland R15239229) gets hot (more than 50 degrees C).

What could be the problem?
Why does it go crazy only after the circuit warms up? Could it be due to a blown capacitor, resistor or IC?

Any help/pointers would be of great help.

See more | Go to post

Last edited by SMDFlea; 06-27-2023, 02:04 AM. Reason: Added "JV-90" to thread title
maleksa replied to Panasonic TH-L42U5K standby voltage help

in Troubleshooting TVs and Video Sources

03-18-2023, 07:28 PM
Re: Panasonic TH-L42U5K standby voltage help

Apologies guys. Here are pics of the entire back of the TV, the power board and the main board.

Cheers...

See more | Go to post
Leave a comment:
maleksa replied to Panasonic TH-L42U5K standby voltage help

in Troubleshooting TVs and Video Sources

03-17-2023, 09:09 PM
Re: Panasonic TH-L42U5K standby voltage help

The voltages on the various pins are as follows

Pin 16 - Fluctuates between 2.25V to 0.14V
Pin 12 - Fluctuates between 3.3V to 0V
Pin 11 and 10 - 4.7V
Pin 9, 8, 4 and 3 - 0V

Appreciate your help/pointers...

See more | Go to post
Leave a comment:
maleksa started a topic Panasonic TH-L42U5K standby voltage help

in Troubleshooting TVs and Video Sources

03-16-2023, 10:47 PM
Panasonic TH-L42U5K standby voltage help

The TV wont turn on and when power is plugged in, the LED will turn from Green to Red and then one Green blink before repeating (Green to Red and one Green blink).

Any pointers is much appreciated.

I also need help to identify which pin is the standby voltage. I only get the 5V for the 2 pins in the attached picture....

See more | Go to post
maleksa replied to Palit GTX 1070 Ti Vmem

in Troubleshooting Desktop Motherboards, Graphics Cards, and PC Peripherals

01-01-2023, 06:47 PM
Re: Palit GTX 1070 Ti Vmem

Thanks. But the strange thing is that there is no short when I check the resistance at the VCore inductors (about 0.5 Ohms) and I do get about 0.7v at the VCore when I power up the card. Just no voltage at the Vmem inductor....

See more | Go to post
Leave a comment:
maleksa started a topic Palit GTX 1070 Ti Vmem

in Troubleshooting Desktop Motherboards, Graphics Cards, and PC Peripherals

12-28-2022, 02:23 AM
Palit GTX 1070 Ti Vmem

The voltage of my Palit GTX 1070 Ti's Vmem is 0V. The rest of the voltage rails (including Vcore) is present.

The resistance of Vmem to ground measured at the inductor is only about 6 ohms. When I injected about 1.2V at Vmem, the core heats up to just below 40C.

Does this mean I have a shorted core?

See more | Go to post
maleksa replied to SMD marking 54D1E

in General Electronics Technical Discussion

12-05-2022, 03:13 AM
Re: SMD marking 54D1E

Fantastic! Thanks...

See more | Go to post
Leave a comment:
maleksa started a topic SMD marking 54D1E

in General Electronics Technical Discussion

12-04-2022, 07:51 PM
SMD marking 54D1E

Can someone help me identify this component?

It is on Synology DS218+ motherboard.

Thanks in advance!...

See more | Go to post
maleksa replied to LG 60PA6500 Plasma Mainboard

in Troubleshooting TVs and Video Sources

09-03-2017, 08:59 AM
Re: LG 60PA6500 Plasma Mainboard

Thanks for the pointer tom66. Will give it a try......

See more | Go to post
Leave a comment: