Unable to flash new DevKetC - older DevKetC works fine

[wevets]

I have been running code on a ESP32 (Rev 1) DevKitC for a while that I had been given by someone else who had also been developing code on it. Flash, test, flash test.... the usual cycle.

I bought a new DevKitC from Amazon which, when I pluged in, powered up and monitored through COM3, reports scanning the local WiFi neighborhood and finding several SSID advertisements, like this: (Output from PuTTY at 115200 baud, so I know I can connect to the board.)

"
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:812
load:0x40078000,len:0
load:0x40078000,len:10212
entry 0x40078a00
Setup done
scan start
scan done
10 networks found
1: FBI Surveillance Van (-51)*
2: HOME-7C3B-2.4 (-69)*
3: xfinitywifi (-71)
4: Carter1 (-79)*
5: LeoK (-79)*
6: xfinitywifi (-80)
7: xfinitywifi (-81)
8: DIRECT-roku-240-D70321 (-82)*
9: FunkyTown (-92)*
10: xfinitywifi (-95)
"

And then it repeatedly reports scan results.

When I try to flash the new DevKitC using exactly the same tools and procedures (make flash) that worked on the older DevKitC, the attempt times out with the following error message:

"
A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header
make: *** [/home/Steve/esp/esp-idf/components/esptool_py/Makefile.projbuild:78: erase_flash] Error 2
"
I've tried pressing the on-board "boot" and "en" buttons both separately and simultaneously. I've tried "make erase_flash". No joy.

Then I put the old DevKitC with the Rev 1 ESP32 back on the breadboard - no changes to any wiring - and things worked just fine.

Is there something that I'm missing in getting this new DevKitC to accept a flash? Or do I have a defective DevKitC?

[WiFive]

With putty open can you get it to boot into download mode with the buttons?

[wevets]

I don't believe so. PuTTY conflicts with COM3 access by the boot loader. That is, if PuTTY is running, the boot loader can't see the DevKitC, and vice versa.
When PuTTY is running, I can get the board to reset and restart it's internal program, the one that scans SSDs. It resets like this when I hit Boot alone or Boot and En simultaneously. But with PuTTY down, when I hit Boot and/or En, the board won't go into download mode either. I get the error msg reported above.

[wevets]

Fixed! More or less. I've found that if I press the boot button during the entire flash process, this board accepts a flash. A pain, but not fatal. My other DevKetC's don't require this treatment.